Santos José Ferreira, Caetano Filomena, Parreira Leonor, Madeira João, Cardoso Paula, Fonseca Nuno, Segurado Filomena, Soares Luís Neves, Inês Lopes
Serviço de Cardiologia do Hospital de São Bernardo, Setúbal, Portugal.
Rev Port Cardiol. 2003 Nov;22(11):1363-71.
Ventricular resynchronization therapy optimizes cardiac function and induces reverse remodeling of the left ventricle (LV) in patients (pts) with dilated cardiomyopathy and intraventricular conduction disturbances. Improvement of LV mechanical synchrony seems to be the predominant mechanism. There is a growing interest in objective quantification of desynchronization. This study aims to evaluate the effect of ventricular resynchronization therapy on LV remodeling and on LV desynchronization, assessed by tissue Doppler echocardiography.
We studied ten pts, eight male, mean age 65 +/- 10 years, with dilated cardiomyopathy, intraventricular conduction disturbances and heart failure, New York Heart Association functional class III or IV. Five pts had coronary artery disease and the others idiopathic dilated cardiomyopathy. All pts had an implanted cardioverter, defibrillator with cardiac resynchronization therapy. The LV pacing electrode was placed in the lateral or posterolateral vein.
Before and one month after resynchronization therapy the following parameters were measured with conventional Doppler echocardiography: LV end-diastolic (LVd) and end-systolic (LVs) size, ejection fraction (EF) and mitral regurgitation (MR) area. For diastolic function the maximum velocity of the E wave (MV-E) and A wave (MV-A), E/A ratio, LV filling time (LV-FT) and isovolumetric relaxation time (IVRT) were meadured. Mitral longitudinal motion was studied with pulsed tissue Doppler. Maximum velocity of the systolic S wave (MV-S) and isovolumetric contraction time (IVCT) were measured in the tissue Doppler curve of the septum and lateral, inferior and anterior walls. To evaluate the degree of desynchronization the RV index was calculated for each patient, based on the difference between the maximum and minimum IVCT, normalized for the maximum IVCT.
There was a significant reduction in LVd and MR. EF increased significantly (p = 0.003). There were no differences in diastolic function parameters. MV-S did not increase significantly. IVCT increased significantly at the lateral wall (p = 0.037). The RV index demonstrated a significant reduction in ventricular desynchronization (p = 0.001).
Ventricular resynchronization therapy induces reverse remodeling and improves LV function in selected pts. Improvement of mechanical LV synchrony seems to be the predominant mechanism. Ventricular desynchronization can be measured by tissue Doppler echocardiography.
心室再同步治疗可优化心脏功能，并使扩张型心肌病和室内传导障碍患者的左心室（LV）发生逆向重构。左心室机械同步性的改善似乎是主要机制。目前，人们对失同步的客观量化越来越感兴趣。本研究旨在通过组织多普勒超声心动图评估心室再同步治疗对左心室重构和左心室失同步的影响。
我们研究了10例患者，其中8例为男性，平均年龄65±10岁，患有扩张型心肌病、室内传导障碍和心力衰竭，纽约心脏协会心功能分级为III或IV级。5例患者患有冠状动脉疾病，其余为特发性扩张型心肌病。所有患者均植入了具备心脏再同步治疗功能的心脏复律除颤器。左心室起搏电极置于外侧或后外侧静脉。
在再同步治疗前及治疗后1个月，采用传统多普勒超声心动图测量以下参数：左心室舒张末期（LVd）和收缩末期（LVs）内径、射血分数（EF）和二尖瓣反流（MR）面积。对于舒张功能，测量E波最大速度（MV-E）和A波最大速度（MV-A）、E/A比值、左心室充盈时间（LV-FT）和等容舒张时间（IVRT）。采用脉冲组织多普勒研究二尖瓣纵向运动。在室间隔、外侧壁、下壁和前壁的组织多普勒曲线上测量收缩期S波最大速度（MV-S）和等容收缩时间（IVCT）。为评估失同步程度，根据每位患者最大和最小IVCT之间的差值计算右心室指数，并将其除以最大IVCT进行标准化。
LVd和MR显著降低。EF显著增加（p = 0.003）。舒张功能参数无差异。MV-S未显著增加。外侧壁IVCT显著增加（p = 0.037）。右心室指数显示心室失同步显著降低（p = 0.001）。
心室再同步治疗可使部分患者发生逆向重构并改善左心室功能。左心室机械同步性的改善似乎是主要机制。心室失同步可通过组织多普勒超声心动图进行测量。
